Conventionally, plants have been deeply involved with human as foods, ornaments, industrial materials such as paper and chemicals, and fuels. Further, recently, plants have been spotlighted as biomass energy that will substitute fossil fuel.
Although plants have been used in such various fields, their mechanisms such as budding, growth, and anthesis have not yet been clarified in many regards. Consequently, cultivation of plants has been mainly based on experiences and intuition, and harvest of the plants has been greatly influenced by natural conditions such as weather. Therefore, clarification of plants' mechanisms such as budding, growth, and anthesis and regulating and controlling the mechanisms are very important not only for increasing yields of ornamental plants and food plants such as grains and vegetables, but also for growing woods in forests and biomass energy.
In order to regulate growth of plants, there have been made attempts such as regulation of anthesis by artificial environments such as a conservatory, and promotion of growth by use of chemicals such as ethylene. However, most of these conventional attempts are regulations of growth of plants based on experiences and intuition, and are not based on data that allows scientific evaluation of growth of plants.
In view of the above, the inventors of the present invention have researched on the plants' mechanisms of budding, growth, and anthesis. Consequently, the inventors have shown that reactive oxygen species (ROS) is essential not only as a substrate for biosynthesis but also as a factor for controlling growth of plants (see Patent Literature 1). Specifically, Patent Literature 1 describes a regulator that contains a redox state regulation substance for cells and that regulates differentiation of cells or organs, a method for controlling differentiation and morphogenesis of a organism, and a organism thus obtained.
Further, Patent Literature 2 discloses an adjuvant for regulating growth of plants and a method for preparing redifferentiated plants by used of the adjuvant. Specifically, a callus induced from a part of a plant such as rice and eustoma is cultivated in a redifferentiating culture medium containing glutathione, preferably oxidized glutathione (which may be hereinafter referred to as GSSG) so as to promote rhizogenesis, effectively obtaining a redifferentiated body from the callus in a short time.